Interaction of electron acceptors with bases. Part XVIII. The dependence of optical evaluations of association constants of electron—donor–acceptor complexes on wavelength

Abstract

Attempts to determine, from optical-density measurements, the association constants of various hydrocarbon–electron acceptor complexes, which show two intermolecular charge-transfer bands, result in values which depend on the wavelength of measurement. It is suggested that only 1:1 complexing occurs, and that the observed dependence of association constants on wavelength is the result of deviations from Beer's law of the intermolecular absorptions characteristic of the complexes under the experimental conditions normally used.